The present invention relates to a cleaning treatment apparatus which cleans an object to be treated (such as a semiconductor wafer) with treatment liquids.
In general, a cleaning treatment apparatus is used during the semiconductor fabrication process to remove chemicals and impurities that have attached to the surfaces of the semiconductor wafers. This cleaning treatment apparatus cleans the surfaces of the semiconductor wafer by subjecting the semiconductor wafer to a sequence of various processes such as ammonia treatment, water washing, and hydrofluoric acid treatment.
A conventional example of such a cleaning treatment apparatus is provided with a row of a plurality of cleaning treatment chambers in which are contained treatment tanks such as an ammonia treatment tank, a water washing treatment tank, and a hydrofluoric acid treatment tank. The semiconductor wafer that is the object to be treated is held and supported by a conveyor means in such a manner that it is conveyed into and out of each of these treatment chambers and is cleaned thereby (as disclosed in, for example, Japanese Utility Model Laid-Open Publication No. 116736-1991). In order to prevent the atmosphere within each of the treatment chambers from leaking out, the periphery of each treatment tank is compartmentalized into a vessel, and each vessel is provided with an opening through which the semiconductor wafers are conveyed in and out. This opening is closed by a opening/closing means such as a shutter, or it is isolated by an air curtain, and thus the atmosphere within each cleaning treatment chamber is prevented from leaking out.
However, since a large number of treatment steps is required, not only must this conventional type of cleaning treatment apparatus be provided with a large number of treatment tanks arrayed for use in the various processes, openings having some means of isolation (such as shutters or air curtains) must be provided between the treatment tanks. Therefore, at the very least there are problems in that the apparatus body is bulky and a large installation space must be provided, and also the treatment efficiency is reduced because the object to be treated is conveyed into and out of the treatment chambers by the conveyor means.
In addition, with this type of cleaning treatment apparatus, in order to convey the semiconductor wafer into and out of treatment chambers with different atmospheres by the conveyor means, chemicals that had operated on the semiconductor wafer and the conveyor means in the previous treatment and are adhered thereto could drip during the conveying within the opening or onto the shutter. Chemicals that drip within the opening could penetrate the seal portion thereof and could even penetrate as far as the shutter drive portion to corrode the drive portion, or dirt generated within the drive portion of the shutter could adhere to the seal portion. This causes problems such that dirt adhering to this seal portion could leak into the opening, dirtying the semiconductor wafers or lowering the yield of semiconductor wafers.